Much in the same way its spiritual predecessor “The X-Files” paired the paranormal with the procedural, “Fringe” — the spectacular sci-fi series created by J.J. Abrams, Alex Kurtzman and Roberto Orci that draws to a close Friday — imagined a world in which the fantastic lay just beyond the grasp of an unknowing populace. But of the many alien, unnatural threats that intrepid agents Mulder and Scully faced on Chris Carter’s landmark 1990s drama, “Fringe’s” time shifts and visits to parallel dimensions weren’t among them.

Indeed, by the time its second season arrived, “Fringe” had established its own unique rhythms and preoccupations as its action centered around Olivia Dunham (Anna Torv), an agent for the FBI’s Fringe Division, a covert operation set up to investigate extraordinary events, and her cohorts, the red licorice-munching, off-kilter scientist Walter Bishop (John Noble) and his brilliant and bold son Peter (Joshua Jackson).

Having long since come to terms with the telekinetic abilities instilled in her as a child, Olivia, along with Walter, Peter and long-suffering assistant Astrid (Jasika Nicole) are now in 2036 — after having been locked in amber like a “Jurassic Park” mosquito for 20 years — hoping to defeat humanity’s conquerors: a group called the Observers who are a possible future evolution of ourselves.

Fight the future, indeed.

Along the way, stunning secrets about their pasts have been revealed and viewers have seen some jarringly different versions of the characters — including Walter’s extra-dimension counterpart, a hard-charging government official referred to as “Walternate.” Peter has even been (temporarily) erased from existence.

Before the climactic adventure, we look back at 10 stellar episodes from the “Fringe” case files – the most thrilling and moving, with some humor and truly weird science, starting from Season 1.

A warning to the uninitiated, spoilers ahead.

“Safe”: The opening fringe event is a memorable one — thieves break into a bank vault by using a device that enables them to walk through walls, but only for a limited time. When one of the burglars can’t make it out quickly enough and becomes trapped, his associates fatally shoot him. Curiously, both Walter and Season 1 baddie David Robert Jones (Jared Harris) have a connection to the safe-deposit boxes the robbers were after. As to what’s inside them, well… Added bonus? The episode concludes with on ominous note, with Jones telling his lawyer to communicate to those outside that Olivia is a target. She’s then abducted and Jones is zapped out of prison.

Leonard Nimoy as William Bell, owner and founder of Massive Dynamics, in “There’s More Than One of Everything,” the Season 1 finale of “Fringe.” (Craig Blankenhorn / Fox)

“There’s More Than One of Everything”: Season 1’s finale went a long way toward stemming “X-Files” comparisons by firmly showing that “Fringe” has its own mythology, and it shocked and delighted viewers with three big reveals: a grave secret about Peter, the appearance of the much-discussed but as-yet-unseen Massive Dynamic founder William Bell, and a first look at the other universe — which David Robert Jones is attempting to access by opening a portal that will lead him there. It doesn’t end well for him, however.

In a treat for sci-fi fans, Leonard Nimoy was cast as Bell, and his first scene is a memorable one. As he emerges from the shadows to greet Olivia, she looks out of the window and the camera pulls back to reveal the twin towers of the World Trade Center still standing.

“Peter”: Near the end of the series’ second season, audiences learn about the incident that’s at the heart of the show’s central story line, an event that ultimately imperils two worlds. When Olivia detects that Peter glimmers like a being from the other side, Walter implores her to keep this truth secret. Then, in one extended flashback set in 1985, we learn that Peter died as a young boy, despite Walter’s attempts to find a cure for his illness.

Grief-stricken in his lab, Walter peers through the window to the other dimension and watches as the other Walter is on the very precipice of finding the cure. Walter decides to cross universes to save the other Peter, and he ends up returning with the other child, but not without incident. When the ice breaks at Reiden Lake, they nearly drown — but the Observer (Michael Cerveris) saves them, saying “The boy is important. He must live.”

After Walter’s wife Elizabeth sees Peter in her husband’s lab, he realizes he can’t rob her of a second chance with her son, he realizes he can’t take the boy back to the other universe, and he grasps the full weight of his decision and the potential fallout from his choice.

“White Tulip”: “Grief can drive people to extraordinary lengths,” Walter fittingly says in this Season 2 episode, one of the series’ most emotionally affecting.

The team becomes involved with the case of Alistair Peck (Peter Weller), an MIT professor whose love Arlette died in a car accident 10 months before. Through his work in theoretical physics and some disturbing self-surgery, the heartbroken Peck has devised a way to travel back in time, though not far enough back to save Arlette. Turns out, though, his time-jumps prove deadly to anyone who’s around him.

The story reboots a couple of times. In one version, Walter corrects Peck’s calculations but asks him not to journey back to the past. He tells Peck about what he did for Peter and that he prays to see a white tulip as a sign of forgiveness. Peck does, in fact, make the jump, but before doing so, he arranges for a letter to be sent to Walter on a particular day. When Walter — now having never met the man — opens the envelope, he finds a drawing of a white tulip.

It’s a poignant moment, one that resurfaced in last Friday’s episode.

A scene from “Over There,” the two-part Season 2 finale of “Fringe.” (Liane Hentscher / Fox)

“Over There Parts 1& 2:” Finally having learned the truth about his past, Peter has traveled back to the other universe, where he interacts with his original mother in an affecting scene.

Quite a lot transpires in the two-part Season 2 finale: Olivia and her alternate-universe counterpart, known as Fauxlivia, fight; Walter and William Bell – seeing each other for the first time in many years – bicker like an old married couple; and Peter realizes that Walternate is lying about saving both worlds and wants to use him to destroy the one we know and love.

But the episodes also have a light touch at times, with some fun different-reality comedy: Told his abduction case is famous, Peter asks Fauxlivia, “So I’m like the Lindbergh baby?” She replies, “The what?”

There’s nothing funny about Olivia’s fate at the episodes’ end, however. Walter’s made it back with Peter to our side, but they’ve mistakenly brought Fauxlivia along. Olivia is locked in a cell, pleading to be let out as Walternate lowers the metal shade, leaving her in total darkness.

“Entrada”: In Season 3, Peter is finally in a relationship with Olivia — only it’s the wrong Olivia and he doesn’t know it. In this episode he learns he’s in bed with Fauxlivia, who’s on a covert mission to help the other side destroy this universe; she forces Peter to inject himself with a sedative at gunpoint. Fringe boss Broyles (Lance Reddick) isn’t pleased when he learns that the Dunham in their midst is actually a spy.

This briskly paced adventure combines the search for Fauxlivia on this side and the fate of Olivia on the other side – the plan is to swap her for Fauxlivia in a cross-universe extraction that the spy would not survive. It’s Other Broyles, though, who pays the ultimate price, after he helps Olivia escape. (In a classic “Fringe” moment, Broyles closes the eyes of his dead doppelganger.) But universe-hopping has taken a toll on Olivia, and in many ways, she’s not the same woman she was.

“The Day We Died”: Things get weird in the Season 3 finale, starting with the fact that Peter finds himself transported to 2026. Life is different here: Olivia is the boss, Astrid (Jasika Nicole) has straight, close-cropped hair, Broyles is a senator and Walter’s in prison, a man reviled around the world for the destruction he’s caused.

The terrorist plot the team is investigating leads to Walternate, who has survived his universe’s destruction and has decided to lay waste to this one as an act of revenge. Walter, on supervised release from a mental institution, tells Peter they can save both universes by using the machine again — “We can cheat the rules of time” — but Walter insists that Peter must make a different choice while in the machine that brought him to this place.

As it happens, Peter’s only been inside the machine for 60 seconds.

He returns to consciousness before the machine amps back up, and in a flash, the Fringe teams from both universes are in the same lab. Peter has brought them together to protect both worlds. Then, he vanishes, having served his purpose.

Olivia, Peter and Walter are stuck in an inescapable town where people are going insane, all because our resident mad scientist wanted a slice of rhubarb pie.

At this point in Season 4, Peter’s returned to corporeal form, though – Peter’s luck being what it is – no one remembers him. But “Westfield” marks the point where the characters begin to truly warm to him in surprising ways. Peter and Walter bond over working together to solve the mystery of what’s happening to the townsfolk, and in a quiet moment, Olivia asks Peter about his Olivia, and he mentions their Friday night tradition, including food from Damiano’s.

At the hour’s conclusion, Peter pops by Olivia’s apartment, and once he’s invited in, he asks her what smells so good. “What do you mean?” she asks. “It’s Friday. I ordered Damiano’s.” And she surprises Peter with a kiss.

Etta (Georgina Haig) battles an Observer in “The Bullet That Saved the World,” a Season 5 episode of “Fringe.” (Liane Hentscher/Fox)

“The Bullet That Saved the World”: It’s 2036. The Observers rule. Peter and Olivia’s daughter, Etta (Georgina Haig), a Fringe Division agent who’s secretly with the resistance movement, frees the team from the amber where they’ve been trapped for 20 years. But the Bishop family reunion is brief. As the team mobilizes and collects weapons from Broyles — a thoroughly decent man in any incarnation — Observer Capt. Windmark (Michael Kopsa) shoots and kills Etta. Peter has now lost a child of his own.

“The Boy Must Live”: Heading into last Friday’s episode, Walter had learned that his mysterious accomplice, Donald, is, in fact, his old Observer friend September. The newest member of their fugitive crew, the child-looking, mute Observer called Michael, had connected with Walter’s damaged mind and shown him things, as well, helping Walter remember the other timeline and feel closer to Peter. The team finds September – who, having been punished by “biological reversion,” is now without Observer abilities.

The resistance plan involves building a device and taking Michael to 2167 to demonstrate that tremendous intelligence and empathy can co-exist, thereby preventing scientists from undertaking the kinds of genetic manipulations that led/lead to the Observers. Olivia believes the plan will bring Etta back as well.

In private, Walter reveals to September that Michael showed him that he must sacrifice himself for the plan to work. Walter’s also figured out that at Reiden Lake all those years ago, September’s statement about “the boy” wasn’t about Peter at all, but about Michael, who was grown from September’s genetic material. September and Michael touch hands, and father tells son he’ll see him again.

With Observers and Loyalists closing in, the team heads to a monorail station, where at the last second Michael steps off the train alone and into Windmark’s custody.

What’s in store for the grand finale? Leave your theories in the comments section below.

Comments

One of the best shows in many years. The visitors from Oz — Anna Torv (incidentally, Rupert Murdoch's niece from his first marriage) and John Noble — have raised the bar for American actors several notches. The writing and production can only be described with superlatives.
Unfortunately, because of its sheer impact, it has achieved cult status, and the usual pedantic Keepers of the Flame, with inside jokes and painstakingly complicated interpretations, are in danger of turning "Fringe" into the stuff scificons are made of, thus chasing away late-comers to the series.